An existing supporting device for installing a display 10 is shown in FIGS. 1, 2 and 3. The supporting device includes an axle seat 12 which is connected to a support arm 11, a coupling seat 13 which is disposed on the axle seat 12, an installation seat 14 which is detachably disposed on the coupling seat 13 and is connected to the display 10, and a quick release structure 15 which is releasably disposed between the coupling seat 13 and the installation seat 14.
The coupling seat 13 has an embedding portion 131 which is connected to the installation seat 14, and a fitting portion 132 which is connected to the quick release structure 15. The installation seat 14 has a slightly disc-shaped base edge 141, four locking portions 142 which extend from the base edge 141, and four locking bolts 143 which pass through the locking portions 142 respectively and are screwed to the locking bolt 143 on the back side of the display 10. The base edge 141 has a semi-circular curved slot 144 for the embedding portion 131 of the coupling seat 13 to be embedded in, and a circular hole 145. The quick release structure 15 has a curved thimble 151 which is pivoted to the base edge 141 and is used for embedding the fitting portion 132, and a pull button 152, which can be pressed and pulled, disposed on a front end of the curved thimble 151 and is able to be embedded in the circular hole 145 of the installation seat 14.
Through an arrangement that the installation seat 14 and the quick release structure 15 coordinate with the coupling seat 13, the display 10 can be installed on the coupling seat 13 or be taken down from the coupling seat 13 by such a supporting device. However, such a supporting device requires the coupling seat 13, the installation seat 14 and the quick release structure 15 coordinating with each other to be disposed between the axle seat 12 and the display 10 to form an embedding structure, which is fairly difficult in structural design and substantially increases the manufacturing cost.